An embodiment relates generally to detection of a snow covered path of travel surface using light subsurface scattering.
Precipitation on a driving surface causes several different issues for a vehicle or a person traveling along a path of travel. For example, snow on a road reduces the coefficient of friction between the tires of the vehicle and the surface of the road resulting in vehicle stability issues. Detection of snow on a road of travel is typically determined by a host vehicle sensing for snow on the road utilizing some sensing operation which occurs when the snow is already impacting the vehicle operation such as detecting wheel slip. As a result, the vehicle must monitor its own operating conditions (e.g., wheel slip) against dry pavement operating conditions for determining whether snow is present. As a result, such systems may wait for such a condition to occur or may introduce excitations to the vehicle for determining whether the condition is present (e.g., generating sudden acceleration to the driven wheels for invoking wheel slip if the precipitation is present).
Another advantage is that the technique described herein can attenuate the influence of ambient lighting condition since an active lighting source used, and at the same time, false detection of white colored dry ground such as salt corrupted dry road in winter can be eliminated.